Teenage girls who are concerned about their weight are more likely to take up smoking, a study suggests.
One in five teenage girls smokes
Research carried out in the United States has found a direct link between a desire to be thin and smoking in young girls.
A survey of 273 girls found those who most wanted to be thin were also most likely to smoke.
In contrast, those who were not worried about their weight were less likely to take up the habit.
The findings are based on two telephone surveys carried out on girls in Massachusetts between the ages of 12 and 15.
In the first survey, which was carried out in 1993, the girls were asked to rate the value they put on being thin.
In the second survey, carried out four years later, they were asked if they had taken up smoking. By this time, almost one in four girls had started to smoke.
The researchers, who were from Boston University and Okayama University in Japan, found that girls who had put a high value on being thin were four times more likely to be smokers.
Of those who smoked, 93% felt it was important to be thin. This compared to just 7% of those who didn't smoke.
However, few girls said they believed smoking helped to keep weight off. This led researchers to conclude that other factors, such as peer pressure, may also play a role in determining which girls were most likely to start smoking.
Nevertheless, they suggested that changing girls' perceptions about being thin could help to stop others from taking up smoking.
Writing in the journal Tobacco Control, they said: "We should pay attention to the social/environmental factors that make girls feel that thinness is a positive value and should intervene in the factors that influence perceived importance of being thin in order to improve adolescent health, especially among girls."
More than one in four 15-year-old girls in Britain smokes regularly. This compares to just one in five boys of the same age.
The anti-smoking charity ASH welcomed this latest study. A spokeswoman said: "It shows up how complex the whole relationship between smoking and self-image is with health behaviour.
"It is not just about what health messages they pick up, it is also about what they pick up from the wider environment - pressure from advertising in girl's magazines and television. All of these have a part to play in what they deem to be desirable."
Lesley King-Lewis, chief executive of the charity Action on Addiction, said a lot of pressure was put on women and girls to confirm to an ideal.
"This research highlights the very damaging effects this can have on young women.
"80% of smokers take up smoking as teenagers and whilst the numbers of adult smokers has declined the number of teenagers smoking has actually increased.
"Young smokers often feel able to ignore health warnings, as the dangers seem a long way off, but girls who think that smoking will improve their appearance are sadly mistaken."